The present invention relates generally to apparatus suitable for calibrating computer monitors to reproduce color images that essentially match said images as they will be printed on different media including various types of papers or textiles.
With the advent of high resolution computer monitors connected to personal computers executing desktop publishing tools, it has become possible and desirable to use the computer monitor as a proof prior to printing, i.e., a prepress image. By first proofing images on a computer monitor, time and expenses can be saved. However, various factors can make the image on the computer monitor less useful for proofing purposes. First, computer monitors are generally controlled by three color control signals that represent red, green and blue (RGB) as opposed to the predominant printing process which uses cyan, magenta, yellow, and black (CMYK). Solutions have been offered in the prior art that provide conversions, using tables, between RGB and CMYK representations of an image. However, these conversions rely upon a standard computer monitor. Unfortunately, computer monitors are not standard. Computer monitors manufactured by different manufacturers or processes respond differently to the same RGB signals, generally in a nonlinear manner to each color (R, G or B). Additionally, computer monitors generally have external controls, e.g., contrast and brightness, that effect their output. Also, an observer's perception of an image on a computer monitor is altered dependent upon ambient illumination. Therefore, to be useful for proofing, a method is required to standardize a computer monitor's output so that a reproduced image will be useful as a color reference to an observer.